not an oncologist, but there are only so many nucleotides in that gene. yes all cancer is personal but they all have similarities. p53 for example, is often inactivated; it is the gene that makes cancer cells suicide. no single mutation causes cancer, it is a combinations of them. in short, our DNA gets mutated daily no matter what we do and if we live long enough cancer will kill us, but some regions are more susceptible and other have no effect (called silent mutations)

there are certain sequences or portions of a chromosome that for reasons we still are trying to understand, are more susceptible to mutation, or damage. For example the Brca1 gene is susceptible to mutation to cause breast cancer

Laurence Klauber, probably the best expert on Rattlesnakes was astounded when he saw them crawling across a snow field in December. He then started studying microclimates. Even on a day with temperatures far below freezing there are places where the temperature can harbor warmth that are difficult for us to see, but insects, mammals, and reptiles have evolved ways to detect these microclimates and make them home.

the lack of the second x chromosome means that many protein and endocrine pathways do not develop. The shield chest is an example, one x chromosome will not give any female breast tissue. You could look at Kleinfelter males as an example of too much x chromosome products are made. As to your specific examples, I've been out of human genetics for a while. sorry if this is not what you are exactly looking for